Carbide die with multiple inserts

ABSTRACT

A drawing die includes an outer steel ring having an axial opening having three different diameters therethrough providing first and second shoulders therebetween. A cylindrical recess is provided by the maximum diameter portion of the opening for receiving a plurality of inner and outer segments arranged in matching sets. At least one wedge receiving slot is provided in each set of inner and outer segments and a wedge in each slot is adapted to bear against the first shoulder. A working bushing having an inner diameter less than the minimum diameter of the axial opening and an outer diameter substantially equal to the intermediate diameter of the axial opening bears against the second shoulder. The wedges are movable axially to force the segments of each set apart to firmly hold the bushing in place.

United States Patent 1 Phillips, Jr.

[ CARBIDE DIE WITH MULTIPLE INSERTS 75 Inventor: William R. Phillips, Jr., North Bergen, NJ.

[73] Assignee: Carmet Company, Pittsburgh, Pa.

Primary Examiner-C. W. Lanham Assistant Examiner-Robert M. Rogers Attorney, Agent, or Firm-Vincent G. Gioia; Robert F. Dropkin 1 Jan. 28, 1975 [57] ABSTRACT A drawing die includes an outer steel ring having an axial opening having three different diameters therethro ugh providing first and second shoulders therebetween. A cylindrical recess is provided by the maximum diameter portion of the opening for receiving a plurality of inner and outer segments arranged in matching sets. At least one wedge receiving slot is provided in each set of inner and outer segments and a wedge in each slot is adapted to bear against the first shoulder. A working bushing having an inner diameter less than the minimum diameter of the axial opening and an outer diameter substantially equal to the intermediate diameter of the axial opening bears against the second shoulder. The wedges are movable axially to force the segments of each set apart to firmly hold the bushing in place.

11 Claims, 3 Drawing Figures CARBIDE DIE WITH MULTIPLE INSERTS This invention relates to drawing and forming dies and more particularly to such dies having one or more inner working bushings of tungsten carbide and/or steel. One common way of assembling such bushings is by hot shrinking. While this method works satisfactorily with smaller dies it is not satisfactory with larger dies such as those having 12 inch diameter working surfaces.

It is therefore an object of my invention to provide a die having mechanical means for holding the working bushings in position.

Another object is to provide such dies in which accurate preloading of the bushing can be obtained over a wide range of pressures.

Still another object is to provide such a die which permits easy assembly and disassembly of the parts.

These and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings which form a part of this specification.

FIG. 1 is a sectional view taken on line l-l of FIG.

FIG. 2 is a sectional view taken on line lI-Il of FIG. 1; and

FIG. 3 is a sectional view taken on line Ill-Ill of FIG. 1.

Referring more particularly to the drawings, reference numeral 2 indicates the die of my invention. The die 2 includes an outer support ring 4 having an axial opening 6 therethrough. The opening 6 has a minimum diameter portion 8, an intermediate diameter portion 10 and a maximum diameter portion 12, thus forming two shoulders 14 and 16. There may also be a narrow large diameter portion 18 at the front face of the die. Received in the maximum diameter portion 12 are six steel internal compression segments 20 and six complimentary steel external compression segments 22. Each of the segments 20 and 22 extends slightly less than 60 so as to provide a slight clearance between their ends. Each segment 20 includes three tapered grooves 24 which cooperate with three similar tapered grooves 26 in the matching segment 22 to form three wedge receiving openings 28. The end of each segment 20 has a slot 30 and the end of each segment 22 has a similar slot 32. A wedge 34 is received in each opening 28 and has threaded openings 36 and 38 in its ends with their axes parallel to the axis of opening 6. The included angle of the wedge surfaces is between 2 and 10. A compression screw 40 preferably having a fine pitch passes through a countersink opening 41 in ring 4 and is threaded into each opening 36. Bushings 42, 44 and 46 are received in opening 6 and have an outside diameter just slightly less than the diameter of the intermediate diameter portion 10. Bushings 42 and 44 are preferably made of steel and bushing 46 of tungsten carbide.

The inside diameter of each segment 20 is ground to the same diameter as bushings 42, 44 and 46. The outside diameter of each segment 22 is ground to the same diameter as maximum diameter portion 12. Clearance between the outside diameter surface of segments 20 and the inside diameter surface of segment 22 is preferably between 0.010 and 0.015 inches per side to permit easy assembly.

The die 2 may be used for any desired purpose, but is especially useful for tube drawing, forming and/or sizing. In one particular installation the die 2 may be assembled with a steel adapter ring 50 having an axial opening 52 therethrough with a counterbored portion 54 for receiving bushing 46. The die 2 and adaptor ring 50 are held in place in a housing 56 in any suitable manner such as by means of screws 58. The invention may also be used with tools other than dies.

Die 2 is assembled as follows: With the back end of the ring 4 facing upwardly all of the segments 20 and 22 are placed in opening 6 with their forward ends against shoulder 16 and with the inner diameter surface of segments 20 outwardly from intermediate diameter portion 10. Bushing 42 is then positioned in opening 6 against shoulder 14 and bushings 44 and 46 positioned in abutting positions as shown. The wedges 34 are then inserted in openings 28 and tapped lightly to lock them in place. The compression screws 40 are then screwed through openings 41 into openings 36 and tightened to secure bushings 42, 44 and 46 firmly in place. The die is then ready for operation.

To disassemble, all the compression screws 40 are removed and extraction screws (not shown) are screwed into openings 38 with their heads against the ends of segments 20 and 22 to extract the wedges 34 from openings 28. The bushings 42, 44 and 46 can then be readily removed.

If desired, all the wedges can be assembled simultaneously by extending their length beyond the back end of ring 4 a slight amount equal to the required travel. A heavy plate is then placed over the extended end of the wedges and pressure applied thereto by means of a press ram. Preferably, the wedges would be fully engaged when flush with ring 4. To remove the wedges, pins are inserted in holes 36 and extend beyond the front face of the die 2 a distance equal to or greater than wedge travel. Pressure is then applied to a plate placed over the ends of these pins to push the wedges from openings 28.

Although the invention has been shown in connection with certain specific embodiments, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

What I claim is:

l. A tool assembly comprising an inner member having a cylindrical outer surface, an outer member surrounding said cylindrical outer suface and having a cylindrical inner surface of substantial greater diameter than the diameter of said cylindrical outer surface, a cylindrical recess in one of said members extending around the circumference thereof with its bottom forming one of said cylindrical surfaces, a plurality of inner and outer segments in said cylindrical recess, each of said inner segments being arranged in matching set relationship with an outer segment, the combined radial thickness of matching inner and outer segments being less than the radial distance between said cylindrical inner and outer surfaces, at least one wedge receiving slot being provided in each matching set of inner and outer segments, a wedge in each of said slots, and means for moving said wedges in an axial direction to force'the outer segments into tight engagement with said cylindrical inner surface and the inner segments into tight engagement with said cylindrical outer surface so as to firmly secure said inner and outer members together.

2. A tool assembly according to claim I in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360, the outer surface of each outer segment has a diameter substantially euqual to the diameter of said cylindrical inner surface, and the said cylindrical inner surface has a diameter substantially equal to the inner diameter of said inner segments.

3. A die assembly comprising an outer ring having an axial opening therethrough, an enlarged diameter portion in said opening providing a cylindrical recess, a plurality of inner and outer segments in said cylindrical recess, each of said inner segments being arranged in matching set relationship with an outer segment, a bushing having an inner diameter less than the smallest diameter of said opening, said bushing being received within said axial opening, the combined radial thickness of matching inner and outer segments being less than the radial distance between said bushing and said cylindrical recess, at least one wedge receiving slot being provided in each matching set of inner and outer segments, a wedge in each of said slots, and means for moving said wedges in an axial direction to force the outer segments into tight engagement with the surface of said enlarged diameter portion and the inner segments into tight engagement with said bushing so as to firmly secure said bushing and outer ring together.

4. A die assembly according to claim 3 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.

5. A die assembly according to claim 3 in which each of said slots includes a tapered groove in the inner surface of the outer segment, and a tapered groove in the outer surface of the inner segment.

6. A die assembly according to claim 5 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.

7. A die assembly according to claim 3 including an intermediate diameter portion in said axial opening, a first generally radical shoulder between the enlarged diameter portion and said intermediate diameter portion, and a second generally radial shoulder between said intermediate diameter portion and the minimum diameter portion of said axial opening, said wedges being adapted to bear against said first shoulder, and said bushing being adapted to bear against said second shoulder.

8. A die assembly according to claim 7 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.

9. A die assembly according to claim 7 in which each of said slots includes a tapered groove in the inner surface of the outer segment, and a tapered groove in the outer surface of the inner segment.

10. A die assembly according to claim 9 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.

11. A die assembly comprising an outer ring having an axial opening therethrough, said opening having minimum diameter, intermediate diameter and maximum diameter portions providing a first generally radial shoulder between the maximum and intermediate diameter portions and a second generally radial shoulder between the minimum and intermediate portions, a plurality of outer segments and a like number of matching inner segments arranged in said maximum diameter portion, the combined arcuate length of the inner segments and the combined arcuate length of the outer segments being less than 360, each inner segment being arranged in matching set relationship with an outer segment, the combined radial thickness of the inner and outer segments of each set being less than one-half the difference between said maximum and intermediate diameter portions, the outer surface of each outer segment having a diameter substantially equal to the diameter of said maximum diameter portion, a plurality of tapered grooves in each of said inner and outer segments of each set arranged in matching relationship to provide a plurality of wedge receiving slots, said segments being adapted to bear against said first shoulder, a wedge in each of said slots, a plurality of bushings in said opening arranged in abutting relationship with each other and with said second shoulder, the inner diameters of said bushings being less than said minimum diameter of said opening and the outer diameters of said bushings being substantially equal to the inner diameter of said inner segments, and means for moving said wedges in an axial direction to force the outer segments into tight engagement with the surfaces of said enlarged diameter portion and the inner segments into tight engagement with said bushings. 

1. A tool assembly comprising an inner member having a cylindrical outer surface, an outer member surrounding said cylindrical outer suface and having a cylindrical inner surface of substantial greater diameter than the diameter of said cylindrical outer surface, a cylindrical recess in one of said members extending around the circumference thereof with its bottom forming one of said cylindrical surfaces, a plurality of inner and outer segments in said cylindrical recess, each of said inner segments being arranged in matching set relationship with an outer segment, the combined radial thickness of matching inner and outer segments being less than the radial distance between said cylindrical inner and outer surfaces, at least one wedge receiving slot being provided in each matching set of inner and outer segments, a wedge in each of said slots, and means for moving said wedges in an axial direction to force the outer segments into tight engagement with said cylindrical inner surface and the inner segments into tight engagement with said cylindrical outer surface so as to firmly secure said inner and outer members together.
 2. A tool assembly according to claim 1 in which The combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360*, the outer surface of each outer segment has a diameter substantially euqual to the diameter of said cylindrical inner surface, and the said cylindrical inner surface has a diameter substantially equal to the inner diameter of said inner segments.
 3. A die assembly comprising an outer ring having an axial opening therethrough, an enlarged diameter portion in said opening providing a cylindrical recess, a plurality of inner and outer segments in said cylindrical recess, each of said inner segments being arranged in matching set relationship with an outer segment, a bushing having an inner diameter less than the smallest diameter of said opening, said bushing being received within said axial opening, the combined radial thickness of matching inner and outer segments being less than the radial distance between said bushing and said cylindrical recess, at least one wedge receiving slot being provided in each matching set of inner and outer segments, a wedge in each of said slots, and means for moving said wedges in an axial direction to force the outer segments into tight engagement with the surface of said enlarged diameter portion and the inner segments into tight engagement with said bushing so as to firmly secure said bushing and outer ring together.
 4. A die assembly according to claim 3 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360*, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.
 5. A die assembly according to claim 3 in which each of said slots includes a tapered groove in the inner surface of the outer segment, and a tapered groove in the outer surface of the inner segment.
 6. A die assembly according to claim 5 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360*, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.
 7. A die assembly according to claim 3 including an intermediate diameter portion in said axial opening, a first generally radical shoulder between the enlarged diameter portion and said intermediate diameter portion, and a second generally radial shoulder between said intermediate diameter portion and the minimum diameter portion of said axial opening, said wedges being adapted to bear against said first shoulder, and said bushing being adapted to bear against said second shoulder.
 8. A die assembly according to claim 7 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360*, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.
 9. A die assembly according to claim 7 in which each of said slots includes a tapered groove in the inner surface of the outer segment, and a tapered groove in the outer surface of the inner segment.
 10. A die assembly according to claim 9 in which the combined arcuate length of the inner segments and the combined arcuate length of the outer segments is less than 360*, the outer surface of each outer segment has a diameter substantially equal to the diameter of said maximum diameter portion, and the outer diameter of said bushing is substantially equal to the inner diameter of said inner segments.
 11. A die assembly comprising an outer ring having an axial opening therethrough, Said opening having minimum diameter, intermediate diameter and maximum diameter portions providing a first generally radial shoulder between the maximum and intermediate diameter portions and a second generally radial shoulder between the minimum and intermediate portions, a plurality of outer segments and a like number of matching inner segments arranged in said maximum diameter portion, the combined arcuate length of the inner segments and the combined arcuate length of the outer segments being less than 360*, each inner segment being arranged in matching set relationship with an outer segment, the combined radial thickness of the inner and outer segments of each set being less than one-half the difference between said maximum and intermediate diameter portions, the outer surface of each outer segment having a diameter substantially equal to the diameter of said maximum diameter portion, a plurality of tapered grooves in each of said inner and outer segments of each set arranged in matching relationship to provide a plurality of wedge receiving slots, said segments being adapted to bear against said first shoulder, a wedge in each of said slots, a plurality of bushings in said opening arranged in abutting relationship with each other and with said second shoulder, the inner diameters of said bushings being less than said minimum diameter of said opening and the outer diameters of said bushings being substantially equal to the inner diameter of said inner segments, and means for moving said wedges in an axial direction to force the outer segments into tight engagement with the surfaces of said enlarged diameter portion and the inner segments into tight engagement with said bushings. 